Improving Your Time Trial Performance :: Part Two

In Part One we looked at how to lift your effort to its maximum level and how best to pace yourself to improve your time trialling performance. Now we’ll work on another of the biggest factors – aerodynamics.

You could train hard to become ultra-fit, you could master the art of efficient pacing, and you could reach super-human levels of effort. However, you’ll throw it all away if you don’t address aerodynamics intelligently.

Aerodynamics

First, let’s look at where all your pedalling power goes. Even at quite modest racing speeds, by far the biggest resistance to the forward motion of you and your bike is air resistance - it’s a much more significant force than the rolling resistance of your tyres or the bike’s mechanical inefficiency (e.g. the energy lost from turning the cranks, the chain, wheel bearings and any other components).

Just as being streamlined through the water is vital for fast swimming, being as slippery as possible through the air is the key to going faster on the bike. And the faster you are, the more aerodynamics matter, because air resistance increases exponentially with speed.

To use a real-world example: let’s imagine that a cyclist on our 10 mile Audley End course can manage it in 28 minutes - that’s an average of about 21.5 mph. How much more power do you think they’d need to produce in order to improve to 24 minutes (which is an average of 25 mph)? To increase average speed by 3.5 mph (that’s 16%) takes roughly 40% more power! And, at the elite end of the spectrum, to achieve a 20 minute ride (averaging 30 mph) would need well over twice the power (!) needed for that 28 minute ride... So as you ride faster, the more benefit there is to be gained from good aerodynamics.

The reason why investing in a £3,500 super-bike is not the key to going faster is because the bike itself (any bike) has little air resistance compared to the human being that sits on top of it. If you look at a good photo of a direct, head-on view of a time triallist or triathlete you’ll see that the bike has a tiny frontal area compared to the rider’s body. Some bikes *are* actually more aerodynamic than others, as we’ll see when we look at equipment, but the key to good aerodynamics (and therefore fast cycling) is your riding position: i) minimising your frontal area and ii) forming a shape that air will flow around as easily as possible.
I see plenty of triathletes at all levels using expensive equipment but with very poor aerodynamics. Training hard in the pool for six months might result in knocking a very small amount off your total race time, whereas some simple changes to riding position could reduce your overall time by a much bigger chunk – especially as the cycle leg is such a long part of most triathlons. There’s a lot of “free speed” available...
For elite riders this can be a very sophisticated process involving wind tunnels, lots of testing using power meters, and plenty of experimentation with tiny changes. However, for most of us here are the main areas to start with:-

Long and low

Many triathletes sit up very high, with their bodies acting like sails catching the wind. It’s very useful to see good side-on and head-on views of yourself riding in your time trial position. One rapid WaldenTRI member believed he had quite a low position until we found a side-on race photo that showed his true position. You shouldn’t blindly copy elite time triallists and triathletes though because what works for them may not be right for you, but compare a side-on photo of your own position with some good role models to give yourself some food for thought.

Just like swimming, the longer & straighter that you can make yourself the less resistance there will be. Assuming that you’re using aero bars (“tri bars”), mount them in a position that allows you to keep your back as flat and level to the ground as possible. This will minimise your frontal area and also put your body in a more slippery position.

This is often difficult to achieve if you use a standard road bike with clip-on aero bars instead of a purpose-made time trial bike, especially if you are not very tall, because you simply can’t adjust the handlebars low enough – if you are small the bars’ arm-rests might even be at the same height as your saddle. In that case you don’t have many options other than fitting the clip-on aero bar extensions further forward so you are in more of a stretched out “Superman” position which will bring your body lower. There are several reasons why that’s not ideal though.

If you’re a short rider who races on a dedicated time trial bike you have more options. Do a Google image search for “Emma Pooley time trial position” and you’ll see how a *very* short rider manages to adopt an excellent low, aero position. Short riders should consider buying a very steeply sloping stem (or an adjustable stem) to get their handlebars low enough.

As well as lowering their bars, some riders like to move their saddle slightly forwards and raise its height a little too. That opens up the hip angle a little which some riders find allows them to develop power more easily and which can make running off the bike less of a shock to the legs. There’s a fashion for extreme forward saddle positions though amongst some triathletes, and I’m not a great fan of that – it upsets the bike’s handling and affects efficient hill climbing. Check out photos of Alistair Brownlee’s saddle position in his rare non-drafting events and you’ll see that his saddle is not very far forward. It’s a good example.
Only ever change your position very gradually, probably no more than 5mm at a time, and only change it further once you’ve ridden several times without any aches and pains. It can take a long time to adapt. You might need to work on your flexibility & strength too: as a (much) younger rider I could race in a very low position without any problems, but it’s a different story now that I don’t look after myself very well! In particular, your triceps, shoulders, neck muscles and hamstrings might protest if you don’t handle it carefully.
Bear in mind that lower isn’t always faster, because there comes a point beyond which you can’t produce as much power. Producing a little more power in a slightly less aero position might actually result in faster times. It’s a balance. Michael Hutchinson is probably the country’s most successful ever UK-based time triallist, and he sometimes raises his bars a few centimetres when riding 10 mile events so that he can produce a higher power for them. However, in longer events (100 miles for example, which still only takes him 3 hrs 20 minutes...) he will use a lower position where good aerodynamics are more important than very high power.

Narrow as an arrow

Again, just like swimming, try to keep yourself narrow to minimise your frontal area and improve your streamlining. That means keeping your fore-arms and hands as close together as possible providing you are still comfortable and can control your bike well.

As a starting point mount the aero bars so that your fore-arms are level. If you have a time trial bike with bar-end gear levers, make sure you’re able to change gear without changing your position.

Experiment with tucking your shoulders forward a little too. We are all different though and, as with all aspects of riding position, you need to find what works best for you as an individual – that’s why bike-fit services like Retül don’t necessarily result in the best time trial position for everyone.

Duck!

Your head catches a lot of air, and that’s before you make it nearly twice its normal size by putting a great big aero helmet on it (more on that later...) So tuck your head down to keep it out of the wind. For safety it’s essential that you are able to look ahead while riding though. With a low riding position and your head tucked out of the way you’ll need to get used to your eyes looking “up” in order to see the road ahead of you, and that can put a strain on the eye muscles. It’s another reason to change your position gradually, not suddenly.

Try not to move out of your aero position during a race unless you need to move your hand position to use the brakes, or to take a drink or a gel. Every time you come out of position you’ll lose a little time. If you need a break from the position though, especially in a long event, try to do this when riding uphill – especially if the hill is steep enough that you are better off riding out of the saddle. That’s when aerodynamics matter much less because you’re travelling more slowly. On our Audley End course the little hill that kicks up through Littlebury on the return leg is a good example.

If you find it uncomfortable to maintain the aero position there could be several reasons for that:-

Are you spending enough time riding in that position during training? Don’t just ride your TT bike for races.

You may need to work on your flexibility and upper body strength a little. That’s another good reason to attend the club’s core strength sessions!

You might have altered your position too quickly. Remember, just change your position by small increments, and give yourself enough time to get used to it before changing it further.

Riding position and bike fit is a complex area with lots of inter-related components, and what I’ve written up until this point is just a generic approach to a better aerodynamic position. If you want individual help to optimise your position just get in touch.

I’ve purposefully played down the importance of equipment compared to the aerodynamics of the rider’s body. But that’s not to say you should just throw away any potential gains in this area, especially if they don’t cost much money. British Cycling’s much-quoted “aggregation of marginal gains” makes a real difference here. So in the next part I’ll look at how you can use equipment to go faster without costing a fortune.